This invention relates generally to a structural joist used in building construction. More specifically, this invention relates to a specific type of parallel chorded truss commonly known as a joist, having an I-beam configuration, which is typically used for supporting floors, ceilings, internal walls and the like.
It is common practice in the building construction industry to used parallel chorded trusses as long span floor or ceiling joists. These trusses typically are formed from parallel flanges separated and connected by a plurality of wooden cross-bracing web members. These trusses provide good access to mechanical elements, such as plumbing, electrical services, HVAC ducts and the like. This allows, e.g. the ceiling or floor to be attached directly to the bottom or top parallel flange with the mechanical elements hidden in the ceiling or floor, as the case may be. A disadvantage is that the cost of good quality sawn lumber is rising and such lumber is becoming more difficult to obtain.
Where strength is required to support loads applied primarily in one direction, considerable cost savings can be achieved by using a pre-fabricated wooden I-beam. This design provides the required strength to support compressive and tensile loads generated by the application of a load to the top of the I-beam resting on supporting structure, such as when the beam is used as a rafter or joist. Such an I-beam design uses either sawn lumber or plywood as the parallel flanges and plywood, oriented strand board (“OSB”) or the like for the vertical web member. Other materials, such as metal or sawn lumber could be used for the web material, but these materials could be prohibitively expensive. A tongue and groove, or other type of joint, is used to connect the web member to the parallel flanges.
Unfortunately, this type of I-beam suffers from the drawback that mechanical elements cannot be passed through the web member without cutting an opening in the web member. Although it is possible to cut the web member at the construction site, the potential exists that too much material will be removed from the web member, adversely affecting the structural capability of the I-beam. Some manufacturers are providing an I-beam with a circular hole pre-formed in the solid web material. Such a configuration generally works but it could be improved because the size and location of the round holes does not necessarily balance the strength of the I-beam with the openness of the web material. It would thus be desirable to provide an I-beam that is low cost yet provides the versatility of allowing mechanical elements to pass through the web member. It would also be desirable to provide such an I-beam that is trimmable, to allow standard lengths to be stored in inventory while allowing the builder to trim some material at one or both ends of the I-beam to provide an I-beam of a desired length for a given application.
The I-beam of this invention is formed from a pair of parallel flanges and a continuous web material affixed to and joining the flanges. The web material is formed so as to define a plurality of differently shaped holes therein that provide access for mechanical elements without compromising the compressive and tensile load capability of the I-beam. The web material is preferably formed from OSB and even more preferably ⅝ inch thick OSB. In addition, the I-beam of this invention preferably has one end where the web material is continuous and does not define any openings therein. This portion of the I-beam thus allows the I-beam to be trimmed so standard lengths of the I-beam can be cut to the desired length for the particular application.
The invention will be described in detail in the following description of preferred embodiments with reference to the following figures in which like reference numbers refer to like parts and wherein:
The various aspects of the invention may be embodied in various forms. The following description shows by way of illustration various embodiments in which aspects of the invention may be practiced. It is to be understood that other embodiments may be utilized and structural and functional modifications may be made without departing from the scope of the present invention. In the description of the various embodiments of this invention, any reference to left, right, top and bottom is to be understood to be based on viewing the embodiment as shown in the FIGS.
Each of the various embodiments of the I-beam of this invention includes two parallel flanges 1 that are formed from solid sawn lumber or laminated plies of veneer lumber glued together. The flange members are joined to OSB web material 2. See, e.g.
The arrangement of openings in the web material may take many forms. However, it has been found that, as seen in the FIGS., the initial opening on the left side of the I-beam, i.e. the side opposite to the trimmable portion, and the opening adjacent to the center of the I-beam, which are both rectangular, provide the basis for an opening configuration that is particularly suited for the purposes of this invention. All of the embodiments of this invention have this configuration. The initial opening preferably has a height greater than its width. Preferably, the initial opening has a width of about six and ⅛ inches and a height of about ten and ½ inches. Preferably, the center opening has a width greater than its height. Preferably the center opening has a width of about two feet and a height of about twelve and ⅞ inches.
Except for the smallest length of I-beam, the openings between the initial opening and the center opening and between the center opening and the trimmable portion are preferably triangular. More preferably, the triangular openings are right isosceles triangles. These triangular openings are arranged to maximize the open space in the web material without compromising the structural integrity of the I-beam. A variety of different sized triangular openings can be used for the various lengths of the I-beam of this invention. The different sizes allow different sized pipes to extend through the triangular openings. For example, the triangular openings identified as “A” allow the passage of a pipe having an outer diameter of about seven and ½ inches to extend therethrough. The triangular openings identified as “B” allow the passage of a pipe having an outer diameter of about eight and 7/16 inches to extend therethrough. The triangular openings identified as “C” allow the passage of a pipe having an outer diameter of about nine and 7/16 inches to extend therethrough. The triangular openings identified as “G” preferably have legs about ten inches long, more specifically, nine and ⅞ inches long.
Preferably, the left side of initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about four and ½ feet from the left end of the I-beam. More specifically, this distance is four feet, 5⅛ inches. The center of the left triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and 14 inches. The center of the left circular opening is about four feet from the left end of the I-beam. More specifically, this distance is three feet, 11 and 5/16 inches. The center of the right circular opening is about seven feet from the left end of the I-beam. More specifically, this distance is six feet, 11 and 5/16 inches. The center of the right triangular opening is about eight feet from the left end of the I-beam. More specifically, this distance is eight feet, 15/16 inches.
Preferably, the left side of initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about five and ½ feet from the left end of the I-beam. More specifically, this distance is five feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and ¼ inches. The center of the left B sized triangular opening is about four and ½ feet from the left end of the I-beam. More specifically, this distance is four feet, four and 5/16 inches. The center of the right B sized triangular opening is about eight and ½ feet from the left end of the I-beam. More specifically, this distance is eight feet, six and 5/16 inches. The center of the right A sized triangular opening is about ten feet from the left end of the I-beam. More specifically, this distance is ten feet, 15/16 inches.
Preferably, the left side of the initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about six and ½ feet from the left end of the I-beam. More specifically, this distance is six feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and ¼ inches. The center of the left B sized triangular opening is about four and ½ feet from the left end of the I-beam. More specifically, this distance is four feet, three and ¾ inches. The right leg of the left G sized triangular opening is about six feet from the left end of the I-beam. More specifically, this distance is six feet, ⅛ inch. The left leg of the right G sized triangular opening is about nine feet from the left end of the I-beam. More specifically, this distance is eight feet 10⅜ inches. The center of the right B sized triangular opening is about ten and ½ feet from the left side of the I-beam. More specifically, this distance is ten feet, seven and ⅛ inches. The center of the right A sized triangular opening is about ½ feet from the left end of the I-beam. More specifically, this distance is 12 feet, 15/16 inches.
Preferably, the left side of the initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about seven and ½ feet from the left end of the I-beam. More specifically, this distance is seven feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and ¼ inches. The center of the left B sized triangular opening is over four feet from the left end of the I-beam. More specifically, this distance is four feet, two and 5/16 inches. The center of the left C sized triangular opening is about five and ½ feet from the left end of the I-beam. More specifically, this distance is five feet, seven and ⅝ inches. The left small triangular opening is located between the C sized triangular opening and the center opening and is preferably about 7 feet from the left end of the I-beam. More specifically, the right leg is seven feet, one and ⅛ inches from the left end of the I-beam. The left leg of the right small opening is about nine and ½ feet from the left end of the I-beam. More specifically, this distance is nine feet, nine and ⅛ inches. The center of right C sized triangular opening is about 11 feet from the left side of the I-beam. More specifically, this distance is 11 feet, two and ⅝ inches. The center of the right B sized triangular opening is about 12 and ½ feet from the left end of the I-beam. More specifically, this distance is 12 feet, seven and 15/16 inches. The center of the right A sized triangular opening is about 14 feet from the left end of the I-beam. More specifically, this distance is 14 feet, 15/16 inches.
Preferably, the left side of initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about eight and ½ feet from the left end of the I-beam. More specifically, this distance is eight feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and ¼ inches. The center of the left B sized triangular opening is about four and 1 feet from the left end of the I-beam. More specifically, this distance is four feet, six and 5/16 inches. The center of the left C sized triangular opening is about six feet from the left end of the I-beam. More specifically, this distance is five feet, 11 and 15/16 inches. The center of the second left B sized triangular opening is about 7 and ½ feet from the left end of the I-beam. More specifically, the distance is seven feet, five and ½ inches. The center of the first right B sized triangular opening is about 11 and ½ feet from the left end of the I-beam. More specifically, this distance is 11 feet, 5 inches. The center of right C sized triangular opening is about 13 feet from the left end of the I-beam. More specifically, this distance is 12 feet, ten and 15/16 inches. The center of the second right B sized triangular opening is about 14 and ½ feet from the left end of the I-beam. More specifically, this distance is 14 feet, four and ⅞ inches. The center of the right A sized triangular opening is about 16 feet from the left end of the I-beam. More specifically, this distance is 16 feet, 15/16 inches. Preferably, the adjacent legs of the A sized triangular openings and the B sized triangular openings are at least about ½ foot apart. More specifically, measured parallel to the flanges, this distance is 9.64 inches, while measured along the line perpendicular to the legs of the triangular openings, this distance is 6 and 13/16 inches.
Preferably, the left side of initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about nine and ½ feet from the left end of the I-beam. More specifically, this distance is nine feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and 15/64 inches. The center of the left B sized triangular opening is about four and ½ feet from the left end of the I-beam. More specifically, this distance is four feet, six and 77/256 inches. The center of the first left C sized triangular opening is about six feet from the left end of the I-beam. More specifically, this distance is five feet, 11 and 171/256 inches. The center of the second left C sized triangular opening is about 7 and ½ feet from the left end of the I-beam. More specifically, the distance is seven feet, five and 73/128 inches. The right side of the left G sized triangular opening is about nine feet from the left end of the I-beam. More specifically, this distance is nine feet, one and ⅛ inches. The left side of the right G sized triangular opening is about 12 feet from the left end of the I-beam. More specifically, this distance is 11 feet, nine and 81/256 inches. The center of first right C sized triangular opening is about 13 and ½ feet from the left end of the I-beam. More specifically, this distance is 13 feet, five and 37/256 inches. The center of the second right C sized triangular opening is about 15 feet from the left end of the I-beam. More specifically, this distance is 14 feet, 11 and 81/256 inches. The center of the right B sized triangular opening is about 16 and ½ feet from the left end of the I-beam. More specifically, this distance is 16 feet, four and 227/256 inches. The center of the right A sized triangular opening is about 18 feet from the left end of the I-beam. More specifically, this distance is 18 feet, 61/64 inches. Preferably, the adjacent legs of the A sized triangular openings and the B sized triangular openings are at least about ½ foot apart. More specifically, measured parallel to the flanges, this distance is 9.64 inches, while measured along the line perpendicular to the legs of the triangular openings, this distance is 6 and 13/16 inches.
Preferably, the left side of initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 12 and 1/16 inches. Preferably the left side of the center opening is about ten and ½ feet from the left end of the I-beam. More specifically, this distance is ten feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and ¼ inches. The center of the first left B sized triangular opening is about four feet from the left end of the I-beam. More specifically, this distance is four feet, two and ⅞ inches. The center of the second left B sized triangular opening is about five and ½ feet from the left end of the I-beam. More specifically, this distance is five feet, seven and 9/16 inches. The center of the left C sized triangular opening is about seven feet from the left end of the I-beam. More specifically, this distance is seven feet, ⅞ inches. The center of the third left B sized triangular opening is about eight and ½ feet from the left end of the I-beam. More specifically, the distance is eight feet, six and 3/16 inches. The right side of the left G sized triangular opening is about ten feet from the left end of the I-beam. More specifically, this distance is ten feet, one and ⅛ inches. The left side of the right G sized triangular opening is about 13 feet from the left end of the I-beam. More specifically, this distance is 12 feet, nine and ⅛ inches. The center of first right B sized triangular opening is about 14 and ½ feet from the left end of the I-beam. More specifically, this distance is 14 feet, four and 1/16 inches. The center of the right C sized triangular opening is about 16 feet from the left end of the I-beam. More specifically, this distance is 15 feet, nine and ⅜ inches. The center of the second right B sized triangular opening is about 17 feet from the left end of the I-beam. More specifically, this distance is 17 feet, two and 11/16 inches. The center of the third right B sized triangular opening is about 18 and ½ feet from the left end of the I-beam. More specifically, this distance is 18 feet, seven and ⅜ inches. The center of the right A sized triangular opening is about 20 feet from the left end of the I-beam. More specifically, this distance is 20 feet, 15/16 inches. Preferably, the adjacent legs of the A sized triangular openings and the B sized triangular openings are at least about ½ foot apart. More specifically, measured parallel to the flanges, this distance is 6.22 inches, while measured along the line perpendicular to the legs of the triangular openings, this distance is four and 51/128 inches.
Preferably, the left side of the initial opening is about twelve inches from the left end of the I-beam. More specifically, this distance is 11 and 15/16 inches. Preferably the left side of the center opening is about eleven and ½ feet from the left end of the I-beam. More specifically, this distance is eleven feet, five and ⅛ inches. The center of the left A sized triangular opening is about three feet from the left end of the I-beam. More specifically, this distance is two feet, ten and ¼ inches. The center of the left B sized triangular opening is about four and ½ feet from the left end of the I-beam. More specifically, this distance is four feet, six and 5/16 inches. The center of the first left C sized triangular opening is about six feet from the left end of the I-beam. More specifically, this distance is six feet, 15/16 inches. The center of the second left C sized triangular opening is about seven and ½ feet from the left end of the I-beam. More specifically, this distance is seven feet, eight and ⅛ inches. The center of the third left C sized triangular opening is about nine feet from the left end of the I-beam. More specifically, the distance is nine feet, three and 5/16 inches. The right side of the left G sized triangular opening is about 11 feet from the left end of the I-beam. More specifically, this distance is 11 feet, 3/16 inches. The left side of the right G sized triangular opening is about 14 feet from the left end of the I-beam. More specifically, this distance is 13 feet, ten and 3/16 inches. The center of first right C sized triangular opening is about 15 and ½ feet from the left end of the I-beam. More specifically, this distance is 15 feet, seven and ¼ inches. The center of the second right C sized triangular opening is about 17 feet from the left end of the I-beam. More specifically, this distance is 17 feet, two and 11/16 inches. The center of the third right C sized triangular opening is about 19 feet from the left end of the I-beam. More specifically, this distance is 18 feet, ten and 1/16 inches. The center of the right B sized triangular opening is about 20 and ½ feet from the left end of the I-beam. More specifically, this distance is 20 feet, four and ⅞ inches. The center of the right A sized triangular opening is about 22 feet from the left end of the I-beam. More specifically, this distance is 22 feet, 15/16 inches. Preferably, the adjacent legs of the A sized triangular openings and the B sized triangular openings are at least about ½ foot apart. More specifically, measured parallel to the flanges, this distance is 9.64 inches, while measured along the line perpendicular to the legs of the triangular openings, this distance is six and 13/16 inches.
An important aspect of this invention is that the total area of the openings in each of the embodiments does not comprise a significant percentage of the total area of the web member. If too much material is removed from the web member to form the openings therein, the structural integrity of the I-beam will be compromised. It has been found that for the fourth embodiment shown in
The present invention has been described with reference to exemplary embodiments thereof. It will be readily apparent, however, to those skilled in the art that it is possible to embody the invention in specific forms other than those of the exemplary embodiments described above. This may be done without departing from the spirit of the invention. The exemplary embodiments are merely illustrative and should not be considered restrictive in any way.
This application claims the benefit of U.S. Provisional Application Ser. No. 60/868,803 filed Dec. 6, 2006.
Number | Date | Country | |
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60868803 | Dec 2006 | US |